Research On The Influence Of Wind Load On Main Boom Of Truss Crawler Crane

As China’s infrastructure,chemical,and wind power projects have become increasingly large-scaled and structurally lightweight,crawler cranes have also appeared in a variety of complex structural forms.The height of the whole machine has been greatly increased by increasing the boom length,making Crawler crane booms are becoming more and more sensitive to wind loads.Research crawler crane main boom and wind load calculation method has important practical significance of the project and its structural safety and lightweight design.Wind pressure and flow velocity are the direct expressions of CFD numerical simulation wind load of crawler crane boom structure.It changes with factors such as the direction of air flow and the aerodynamic shape of crawler crane boom structure.Understand the changes in wind pressure and flow velocity of crawler crane boom.The characteristic is the theoretical basis for the refined establishment of the calculation method of the wind load of the crawler crane boom.The application of large-scale general-purpose CFD software at home and abroad to study the wind load of cranes is mainly concentrated on tower cranes,gantry cranes,bridge cranes,floating cranes and port cranes,and there is little research on the wind load of crawler cranes.Due to the practical needs of lightweight design of the truss boom of crawler cranes and complex actual working conditions,the influence of wind load on the main boom of truss crawler cranes needs to be further studied.This paper analyzes the current situation and the lack of wind load crane-related research at home and abroad,theoretical calculations for wind loads,numerical simulation,wind tunnel test and field measurement.Due to the high cost,high risk,and difficulty in satisfying the experimental conditions,the field test is not adopted by ordinary designers,and the wind tunnel test is only carried out in some universities and limits R&D personnel from adopting this method.With the development of computer technology and commercial software,the method of simulating fluid flow through numerical calculation has become the new favorite of designers.The application of ANSYS CFX to study the wind load of the crawler crane boom has important engineering practical significance for the lightweight design of boom and safety of the whole crane.The main contents are as follows:(1)The QUY220 crawler crane main boom as the research object,based on the reasonable simplified model,the computational fluid dynamics CFD model of the main boom structure is established,and the 78.16° working condition is selected for analysis.The surface pressure,velocity and other parameters of the main arm structure of the flow field under different wind direction angles.The wind load parameters of the main boom structure of the truss boom are calculated according to the design specifications.The calculation results obtained by GB/T 3811-2008 are compared with the results obtained by computational fluid dynamics numerical simulation.It is found that the CFD numerical simulation method proposed in the article is accurate and effective,and the values are very close.The maximum relative error is 0.019873.This method can be used to simulate the wind pressure of the main boom of truss boom at different wind speeds for more accurate structural design of the main boom of the truss boom.(2)The numerical simulation method of computational fluid dynamics proposed in the article is used to study the wind load under different wind direction angles,and the wind load value and its rules for change of the whole machine under different wind direction angles are obtained.Analyzing the main boom characteristics of the flow field,the results show that the wind load at 45°,135°,225°,and 315° wind direction angles reaches the maximum.When designing the main boom,the influence of wind loads from these angles on the stability of the main boom should be considered.(3)Use Workbench to transfer surface pressure of wind,velocity and other parameters to the solid calculation model,realize the one-way fluid-solid coupling numerical analysis of the main arm structure,extracting displacement,stress and other parameters,and study the wind of 15.5,28.3,55 m/s The effect of load on the main boom.Comparing the calculated results with the CFX simulation results,the crane operates at wind speed of not more than 28.3 m/s,and the displacement caused by the wind speed is relatively small,which is safe.In the non-working state,as the wind speed increases,the proportion of the displacement caused by the wind speed in the total displacement increases rapidly.The overturning moment caused by wind speed gradually increases.When designing the main boom of the truss boom,the influence of the downwind wind load on the overturning of the whole machine and influence of the cross wind direction on the stability of main boom should be considered.